Infineon Technologies CY7C1523AV18-250BZC

Overview

CY7C1523AV18 from Cypress Semiconductor is a 72-Mbit (4M × 18) synchronous pipelined SRAM with DDR-II Separate I/O architecture, operating at 250 MHz clock frequency (600 Mbps data rate), supporting 2-word burst reads/writes, and featuring dual echo clocks (CQ/CQ) for precise high-speed data capture in memory subsystems used in network packet buffers and baseband processing.

For engineers reviewing the CY7C1523AV18 datasheet, CY7C1523AV18 pinout, CY7C1523AV18 application, or CY7C1523AV18 equivalent, this device requires attention to its 165-ball FBGA package, HSTL I/O compatibility, DLL-enabled 1.5-cycle read latency, and dual-clock domain timing for DDR-II SIO interface design.

Technical Context

The CY7C1523AV18 implements a synchronous pipelined architecture with separate read and write ports sharing a common 21-bit address bus (A[20:0]), enabling concurrent access without bus turnaround. It uses two independent input clocks (K/K) for address and control latching and two output clocks (C/C) for synchronized data output, with echo clocks (CQ/CQ) phase-aligned to C/C for receiver-side deskewing.

Internally organized as two 2M × 18 arrays, it supports byte-write select (BWS[1:0]) for selective 18-bit word updates, and includes JTAG 1149.1 test access, ZQ impedance calibration, and DOFF-controlled DLL enable/disable to switch between DDR-II (1.5-cycle latency) and DDR-I (1-cycle latency) timing modes.

Key Specifications

Pinout & Package

Available in a 165-ball Fine-Pitch Ball Grid Array (FBGA) package measuring 15 mm × 17 mm × 1.4 mm with exposed thermal pad, optimized for high-speed signal routing and thermal dissipation in dense memory modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-speed burst SRAM applications.

Compared with CY7C1523AV18-278BZC, this -250BZC variant trades 28 MHz speed headroom for lower power (800 mA vs. 880 mA) and relaxed timing closure; versus IS42S16400F, it delivers deterministic zero-refresh latency and native DDR-II SIO but at higher unit cost and lower density efficiency.

Availability

CY7C1523AV18-250BZC is available at Aetrix Electronics and suitable for network packet buffering, baseband signal processing, high-speed test equipment, and avionics data acquisition requiring stable component supply and long-term industrial lifecycle support.

Supply support for CY7C1523AV18-250BZC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Cypress Semiconductor (now part of Infineon Technologies) designs high-performance memory and programmable solutions for industrial, automotive, and communications markets with emphasis on reliability and signal integrity.

This device belongs to the DDR-II SIO SRAM product line, engineered specifically for deterministic, low-latency, high-bandwidth memory interfacing in FPGA- and ASIC-based systems where bus turnaround overhead and clock skew must be eliminated.

FAQ

What is the function of the DOFF pin on CY7C1523AV18-250BZC?

The DOFF (DLL Turn Off) pin is an active-low control that disables the internal Delay Lock Loop. When pulled LOW, the device operates in DDR-I mode with 1-cycle read latency and maximum frequency reduced to 167 MHz. When tied HIGH (via ≤10 kΩ pull-up), DLL is enabled, delivering 1.5-cycle latency at full 250 MHz operation. This pin must never be left floating or tied directly to GND.

How does the ZQ pin affect output driver performance?

The ZQ pin connects to an external 240 Ω resistor to ground to calibrate the output driver impedance to 48 Ω ±15%, ensuring matched termination for HSTL Class I signaling. If connected directly to VDDQ, it forces minimum impedance (~30 Ω); direct connection to GND or open-circuit is prohibited and will cause undefined output behavior and potential signal integrity failure.

Can CY7C1523AV18-250BZC operate with only a single clock domain?

Yes - when C and C pins are unconnected, the device defaults to single-clock mode using K and K as both input and output clocks. In this mode, read data is driven on rising edges of K/K, and echo clocks CQ/CQ are generated relative to K/K. All timing parameters shift accordingly, and maximum frequency remains 250 MHz, though system-level deskew capability is lost.

What is the purpose of BWS[1:0] in the 4M × 18 configuration?

BWS[1:0] are active-low byte write select signals that enable partial 18-bit word updates: BWS0 controls D[8:0] (first 9 bits), BWS1 controls D[17:9] (second 9 bits). Both must be asserted to write the full 18-bit word; deasserting either leaves its corresponding 9-bit segment unchanged. This allows efficient small-data updates without read-modify-write cycles.